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Merge pull request #416 from david-cermak/fix/modem_undef_mode

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fix(modem): Fixed mode transitions between any state and UNDEF
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david-cermak
2023-11-28 17:11:43 +01:00
committed by GitHub
parent 3f49583761 5396de42d0
commit afbca5343e
5 changed files with 170 additions and 13 deletions
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60
docs/esp_modem/en/README.rst
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@ -81,16 +81,68 @@ Common use cases of the esp-modem are also listed as the examples:
- ``examples/modem_console`` is an example to exercise all possible module commands in a console application.
- ``examples/ap_to_pppos`` this example focuses on the network connectivity of the esp-modem and provides a WiFi AP that forwards packets (and uses NAT) to and from the PPPoS connection.
Working modes
~~~~~~~~~~~~~
Modem devices could work in multiple different modes, esp-modem library
uses these states to describe them:
- Standard modes:
- Command mode -- This mode is used for sending AT commands
- Data or PPP mode -- This mode is used for data communication (to create PPPoS tunnel between the device and the library)
- Multiplexing modes:
- CMUX mode -- This mode creates two virtual channels and uses one for sending AT commands and the other one for data communication.
- DUAL mode -- This mode uses two physical channels the same way as CMUX. This mode is supported only by certain devices, usually with USB interface.
- Manual CMUX modes -- These modes are designed for applications to have better control over CMUX mode transitions. It allows setting up the virtual channels,
switching between channels, transitioning between data and command modes for each channel separately, and exiting the CMUX.
Switching between common modes
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
The diagram below depicts allowed transitions between the most common modes
::
+---------+ +---------+
| COMMAND |<-->| DATA |
+---------+ +---------+
^
|
v
+-------+
| CMUX |
+-------+
Note that it is possible to switch from any mode to the "UNDEF" mode and vice-versa.
Switching between manual modes
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
The diagram below depicts allowed transitions between manual CMUX modes
::
+------------------------------------
| |
+----------+ +-------------+ +------------+ +----------+
| |<-->| MANUAL_DATA |<-->| MANUAL_CMD |<-->| COMMAND |
| CMUX | +-------------+ +------------+ | (CMUX |
| MANUAL | | | MANUAL |
| | +-------------+ | EXIT) |
| |<-->| MANUAL_SWAP |<-------------------->| |
+----------+ +-------------+ +----------+
| |
+-----------------------------------------------------+
Note that transitioning between "MANUAL_DATA" and "MANUAL_CMD" switches the secondary terminal (dedicated to PPP session) and could be used for recovering data communication if PPP session gets dropped.
Extensibility
-------------
CMUX
~~~~
Implementation of virtual terminals is an experimental feature, which
allows users to also issue commands in the data mode, after creating
multiple virtual terminals, designating some of them solely to data
mode, others solely to command mode.
Implements virtual terminals which allow users to also issue commands in the data mode;
after creating two virtual terminals, designating one of them solely to data mode, and
another one solely to command mode.
DTE
~~~